Potassium Iodide Test for Lead on a tapelift

This is a positive test for lead on an environmental tapelift collected in a lead/acid battery recycling
plant. Half of the tapelift was exposed to a drop of potassium iodide which was then blotted off. The tape was dried and then processed as normal.
The particles that turned bright yellow contain lead.

Reflected Darkfield Illumination

Definition/Function:

Lead containing particles on an environmental tapelift can be detected by adding a small droplet of 10% nitric acid which is then blotted off,
followed by a 10% droplet of potassium iodide and blotting that off. The result is a bright flash of yellow on the particles that contain lead.
The tapelift is dried, applied to a clean microscope slide and processed as normal. The lead containing particles can then be identified in the
environment with respect to the other particles in the environment. In this case the lead salts were sparingly soluble in water so the nitric
acid pretreatment was not necessary.